Study on local electronic states of transition metal atoms occupied the centers of octahedral and tetrahedral structures by ATS scattering

2002年，我们研究了赤铁矿（Fe_2O_3）和绿铁矿（Cr_O_3），它们属于相同的刚玉结构。我们利用图库巴光子工厂的同步加速器光束测量了这些晶体在Fe或Cr的k吸收边缘附近的ATS散射。主要结果如下：(1)在两种晶体的边缘下，（003）和（009）都观察到ATS强度；(2)赤铁矿的ATS峰的方位角依赖表现为三保持对称；(3)另一方面，Eskolaite的ATS峰的方位角依赖表现为六保持对称；(4)从方位角依赖我们得出结论，赤铁矿的ATS散射是由四极-四极和偶极-四极转变的干涉引起的；6)赤铁矿的ATS散射是由四极-四极过渡引起的；7)在远离边缘的地方，我们观察到ATS强度的两个方位依赖；7)在Eskolaite中，我们没有观察到这种非谐振ATS散射；8)我们认为，这种非谐振ATS散射是由于磁散射和赤铁矿与Eskolaite的磁性结构差异造成的

In 2002, we studied on Hematite (Fe_2O_3) and Eskolaite (Cr_O_3), which belong to the same crystal structure, corundum structure. We measured ATS scattering from these crystals near the K-absorption edge of Fe or Cr, using synchrotron beams in Photon Factory in Tukuba. The main results are the following1) Just below the edges, (003) and (009) ATS intensities were observed in both crystals2) The azimuthal dependence of the ATS peaks from Hematite showed three-hold symmetry3) On the other hand, six-hold symmetry was observed in Eskolatie4) From the azimuthal dependence, we conclude that the ATS scattering is caused by interference of quadrupole-quadrupole and dipole-quadrupole transitions in Hematite5) In Eskolaite, the ATS scattering is due to quadrupole-quadrupole transition6) In Hematite, two-hold azimuthal dependence of the ATS intensity was observed far from the edge7) But, in Eskolaite, we did not observe such non-resonant ATS scattering8) We conclude these non-resonant ATS scattering is due to the magnetic scattering and the difference in Hematite and Eskolaite caused by their magnetic structure